(1E,4E)-1,5-Bis[2-(trifluoro­meth­yl)phen­yl]penta-1,4-dien-3-one

Dong Ho Park; V Ramkumar; P Parthiban

doi:10.1107/S1600536812051586

. 2013 Jan 4;69(Pt 2):o177. doi: 10.1107/S1600536812051586

(1E,4E)-1,5-Bis[2-(trifluoromethyl)phenyl]penta-1,4-dien-3-one

Dong Ho Park ^a, V Ramkumar ^b, P Parthiban ^a,^*

PMCID: PMC3569239 PMID: 23424462

Abstract

In the title compound, C₁₉H₁₂F₆O, a monoketone derivative of curcumin, both double bonds have a trans conformation. The molecule is mostly planar with all C and O atoms essentially coplanar, with the exception of one benzene ring, which is tilted by 17.18 (1)° with respect to the plane of the remainder of the molecule. The r.m.s. deviation from planarity of the coplanar section is 0.0097 Å. The crystal packing features weak C—H⋯O and C—H⋯F interactions.

Related literature

For the synthesis of chalcones, see: Tully et al. (2001 ▶). For the biological properties of chalcones, see: Buescher & Yang (2000 ▶); Kumar et al. (2003 ▶), Hsu & Cheng (2007 ▶). For their physical properties, see: Fichou et al. (1988 ▶); Butcher et al. (2006 ▶). For similar structures, see: Butcher et al. (2007 ▶); Nizam Mohideen et al. (2007 ▶); Harrison et al. (2006 ▶). graphic file with name e-69-0o177-scheme1.jpg

Experimental

Crystal data

C₁₉H₁₂F₆O
M _r = 370.29
Monoclinic,
a = 11.3123 (12) Å
b = 4.7907 (4) Å
c = 15.1697 (16) Å
β = 101.834 (3)°
V = 804.63 (14) Å³
Z = 2
Mo Kα radiation
μ = 0.14 mm⁻¹
T = 298 K
0.35 × 0.25 × 0.10 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.952, T _max = 0.986
5185 measured reflections
2608 independent reflections
1931 reflections with I > 2σ(I)
R _int = 0.020

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.096
S = 1.04
2608 reflections
235 parameters
2 restraints
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.14 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 2012) ▶; software used to prepare material for publication: SHELXL97.

Supplementary Material

Click here for additional data file.^{(23.5KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812051586/zl2522sup1.cif

e-69-0o177-sup1.cif^{(23.5KB, cif)}

Click here for additional data file.^{(128.1KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812051586/zl2522Isup2.hkl

e-69-0o177-Isup2.hkl^{(128.1KB, hkl)}

Click here for additional data file.^{(6.3KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536812051586/zl2522Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C17—H17⋯F3ⁱ	0.93	2.62	3.399 (4)	141 (2)
C1—H1⋯O1ⁱⁱ	0.93	2.72	3.290 (5)	121 (1)

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

The authors acknowledge the Department of Chemistry, IIT Madras, for the X-ray data collection.

supplementary crystallographic information

Comment

The title compound is a bischalcone, and is a monoketone derivative of curcumin. Curcumin is a naturally abundant beta-diketone derived from the rizome of curcuma longa (Buescher & Yang, 2000). Numerous studies have shown that curcumin possesses multiple pharmacological properties. Several clinical trials of curcumin were carried out in patients with pancreatic cancer, multiple myeloma, rheumatoid arthritis, cystic fibrosis, inflammatory bowel disease, psoriasis, and other disorders (Kumar et al., 2003; Hsu & Cheng, 2007). Since the stereochemistry of the synthesized molecule is an important criterion for its biological actions, it is of of desirable to establish the structure of the synthesized molecule.

Crystalline chalcone derivatives are also of interest due to their their second harmonic generation properties, particularly, their often are good blue light emitters. The NLO properties of the molecules are also associated with their molecular geometry (Fichou et al., 1988; Butcher et al., 2006), and accordingly, a single-crystal XRD study of the title bischalcone was undertaken to obtain detailed information on its molecular conformation.

In the title compound, C₁₉H₁₂F₆O, both double bonds have trans configuration. The molecule is mostly planar with all carbon and oxygen atoms coplanar with the exception of one phenyl ring (C1—C6), which is tilted by 17.18 (1)° against the plane of the remainder of the molecule. The root mean square deviation from planarity of the coplanar section Ph—C=C—C(O)—C=C (C8—C18) is 0.0097 Å.

The bond lengths of the conjugated chalcone backbone C5—C13 [C5–C8 = 1.460 (4), C8–C9 = 1.322 (4), C9–C10 = 1.460 (4), C10–C11 = 1.470 (4), C11–C12 = 1.311 (4) and C12–C13 = 1.456 Å] show alternate localized single and double bonds as in its ortho-chloro analog (Nizam Mohideen et al., 2007). This indicates the absence of delocalization of the double bonds in the chalcone skeleton C5—C13.

The crystal packing of this molecule is stabilized by weak intermolecular C—H···O, C—H···F and C—H···π interactions (Table 1).

Experimental

The title compound, 1,5-bis(2-(trifluoromethyl)phenyl)penta-1,4-dien-3-one was synthesized by a modified procedure of Tully et al. (2001) using the milder base ammonium acetate instead of sodium hydroxide and a better yield (86%) was obtained. 20 mmol of 2-trifluoromethylbenzaldehyde (2.634 ml), 15 mmol of acetone (1.11 ml) and 1 g of ammonium acetate were combined in one-pot and stirred gently in ethanol as the solvent (20 ml). The complete consumption of the starting materials was monitored by TLC. After completion, the reaction mass was filtered, washed with cold ethanol and dried. The compound was characterized by melting point, IR and NMR. The analytical and spectral data are as reported previously (Tully et al., 2001). X-ray diffraction quality crystals of the title compound were obtained by slow evaporation of an ethanol solution.